Hold the bus a minute...the applicant says -
"Although retaining the existing building would have a lesser impact on embodied carbon at the outset, in the long term, replacing the existing building with a more efficient building - which takes advantage of renewable technologies— will reduce the operational energy, and offset the initial carbon outlay, while also offering a higher standard of accommodation with more economical running costs for residents."
Let's just unpack that a little. The existing building is roughly 120 years old. It's not unreasonable for there to have been 'ad-hoc changes' over that length of time. How long will the proposed building need to be there for to actually 'offset the initial carbon outlay'?
Furthermore, the existing building is more than capable to 'taking advantage of renewable technologies'. It's just as simple to add PV to an old roof as a new one. An ASHP will be the same if it's plugged into an old or a new building. With a little bit of careful consideration the fabric could be significantly upgraded and windows etc.. replaced with triple glazed units. Once the building is refurbished to a high energy efficient standard and has renewable technologies plugged in is it actually true to say that a new building will reduce the operational energy. The same people will live in the building so their energy consumption will be what it is. If the heating is marginally more expensive in a newly completed refurb it will be a very, very long time indeed before the new build offsets the embodied carbon associated with demolition and new construction.
If the applicant actually means it's just easier for us to bulldoze this and building a new building that lets us sell flats easily then they should simply say so. Don't be embarrassed about suggesting you are looking to develop the site for profit. But don't try and hide the true motive behind an environmental agenda.
The simple fact is the refurbishment of the building is only 'unviable' for this particular developer. That is not the same as the refurbishment being unviable to all.

Absolute greed this one and nothing else. There is no reason whatsoever (other than profit) why you cant work with the existing building on that site. Sure, it has had some poor quality additions over the years, but these could easily be removed and some contemporary forms added in place. This would ultimately increase the density just perhaps not to the level these developers are seeking. #1 above is completely correct, stop trying to dress this up as something its not. I'm more than willing to accept new development, but not by the removal of attractive and historic buildings to make way for more square boxes.

I have to agree with #1 and #2 on this. I do hope the Planning department dig in and challenge some of the eco statements made here. I might be more sympathetic if the building was on its knees but it really does look to be in reasonable condition. Perhaps its the bleached CGI but in my view the 3 storey box proposed just looks woefully out of place.

I want to agree with #1-#3 but it highlights a pressing need for a set of agreed carbon metrics. What would that look like if 1 dwelling is replaced with 11, densifying a neighbourhood with good access to public transport?

It’s a nice house but the climate crisis throws up some conundrums yet to be settled.

#4 I’m pretty sure we can achieve that without the loss of historic fabric.

A conversion of this site could yield 5 dwellings without the need for demolition.

I agree it could be subdivided but 5 isn’t 11. Which is why we need evidence based decision making, not just subjective claims and counter claims.

Dear Iona,
I don't really think anyone is making subjective claims or counter claims; we're just commenting on the information as presented.
The existing and proposed site plan make it fairly evident that with a bit of creative extension/remodelling the existing property could be adjusted to accommodate all 11 (totally abstract number) apartments. The roof could be removed and still replaced with 'penthouse' level apartments.
The main argument is retention isn't 'unviable', as suggested. It just doesn't work for this particular developer. I've, personally, no problem with the developer making as much money as they wish (they are taking the risk after all). But i would prefer if they were honest about it rather than trying to hide a commercial decision in amongst an environmental justification. All that does is dilute the pressing environmental discussion that needs to happen.